Identifying petroleum products



Patented Jam 8, I946 IDENTIFYING PETROLEUM PRODUCTS Joseph W. Sparks,Hammond, Ind., assignor to Standard Oil Company, Chicago, Ill., acorporation of Indiana No Drawing. Application August 20, 1942, SerialNo. 455,549

mum's. (01. 250-11) The present invention relates to improvements in themarking of normally liquid or solid hydrocarbons, particularly petroleumproducts so that the same can be readily detected when admixed withother materials.

'It is an object of the invention to provide a method whereby admixtureor adulteration of various petroleum products can be detected. Anotherobject'of the invention is to provide petroleum products with a materialwhich will permit the detection or identification of such petroleumproducts when admixed with other petroleum products. Still anotherobject is to provide a rapid means for. determining the presence ofcertain hydrocarbon materials in admixture with other similar materials.Other objects and advantages of the invention will become apparent fromthe following description thereof.

The desirability of being able to determine when certain petroleumproducts are admixed with other petroleum products or other materials isvery great. For example, in pumping crude petroleum from various sourcesthrough pipe lines I it ishighly desirable to be able to determinewhether oil from one source is being mixed with oil from another source.In refinery operations in which various types of oils and various oilfractions are frequently obtained from a central source it is highlydesirable to be able to detect any inter-mixing of various stocks withother stocks. It is also frequently desirable to incorporate in thefinished petroleum products certain substances as "markers" so thatunlawful use or adulteration of such products can be detected.

I have discovered that the addition of very minute uantities ofumbelliferone or umbelliferone derivatives in petroleum productsprovides a very efficient and effective method of attaining the abovestated objects. From about 0.0000000l% to about 0.001% of umbelliferoneor its derivatives such as, for example, beta methyl umbelliferone,alpha, beta dimethyl umbelliferone, or 6-chloro umbelliferone can besuitably employed for this purpose. Umbelliferone and its derivativesare strongly fluorescent infaintly alkaline media and very minutequantities of these may be done by matching the intensity offluorescence given off by the sample being tested with a set ofstandards which will indicate approximatch; the degree of admixture, oradulteration.

Certain petroleum products, particularly certain petroleum crude oils,contain natural iiuorescing materials which mask the fluorescence ofumbelliferone and its derivatives when they are added to such petroleummaterials. Furthermore, the extraction of such petroleum products, suchas crude oil and distillates therefrom, with aqueous acid media,produceextracts which fluoresce when subjected to suitable source oflight. On the other hand, such petroleum products yield, on extractionwith an aqueous alkaline solution, an extract which does not fluorescewhen tested under a source of light. Umbelliferone and its derivativesfluoresces strongly blue in alkaline solution and this property vanishesin acid solutions. Therefore, to detect umbelliferone or itsderivatives, petroleum products containing them are extracted with anaqueous alkaline solution such as an aqueous sodium bircarbonatesolution, and the clear aqueous solution is separated from the oil. Thisclear aqueous solution is then subjected to a suitable source of lightwhereby excitation of fluorescence indicates the presence of theumbelliferone or its derivatives, while the absence of is used,sufllcient of the special crude is pumped materials can be detectedunder "ultraviolet light" such as that obtained with the GeneralElectric type B-4 black bulb. For the detection of adulteration orunlawful use of petroleum products it is suiiicient to determinequalitatively the presence of the umbelliferone or its derivatives inthe material being tested. If for various reasons it is desired to makea quantitative determination of the extent of adulteration 'orintermixing, this so that the first portion of the receipts can beconsidered as a wash to remove the residue left by the previous crude.This wash portion of the new crude is repeated for a period of time,which experience has shown should be sufficient to clean the entireline. However, it is obvious that ,the time required to remove allcontamination may vary from crude to crude, or change with temperatureconditions. Thus there is no certainty as to the exact point at whichthe switch over to uncontaminated crude can be made with safety.

when simultaneous pumpings ar proceeding through different pipes in theline, undesirable crude inay enter the special stream through leak in:valves in the cross-overs, operators mistakes points for variousfractions.

or by contamination in the tanks which are floating on the line.

To detect the presence of undesirable crude in the desired crude oil theformer is marked by adding thereto small amounts of umbelliferone or aderivative thereof such as beta methyl umbellii'erone. Thus. if it isdesired to detect with certainty 1% oi the undesired crude in thedesired crude the former is marked by adding thereto 1 gramo!umbelliferone in acetone solution to each 6.3 barrels oi the'undesiredcrude oil. This solution is equivalent to about 1 gram of the marker in1,000,000 cc. of the oil. To detect the amount of contamination about 75cc. of the suspected crude is extracted with cc. of a saturated solutionof sodium bicarbonate and after settling for about 10 minutes the clearlower aqueous solution is poured into a suitable container and examinedunder ultraviolet light. By. matching the intensity oi the fluorescencewith a setof standards the approximate degree of contamination can bedetermined.

In testing for the presence of the marker, precautions should beexercised to use clean equipment and to avoid the use of alcohol in theextraction. By clean" equipment, such as bottles, I mean equipment whichwhen rinsed out with a saturated soda solution, will not produce afluorescing solution. water is usually suflicient to remove the tracesof the umbelliferone from a previous test.

While this invention is particularly well adapted in detectingcontamination of a crude oil by another crude oil or the contaminationor adulteration of normally liquid or solid petroleum products ingeneral it is also well adapted for use in the distillation ofhydrocarbon mixtures, such as petroleum oils, as well as vegetable andanimal oils or fatty acid mixtures to determine the out This can beaccomplished by adding to the material being distilled umbelliferone orderivatives thereof, having boiling points corresponding to thevolatilizetion characteristics of the desired fractions to be separated.The invention is also well suited for investigating the migration ofcrud oils through oil-bearing strata.

While I have described my invention by a preferred embodiment thereof itis to be understood that the invention is not to be limited therebyexcept in so far as defined by the appended claims.

I claim:

1. The method of detecting the presence of a hydrocarbon in admixturewith other hydrocarbons comprising adding to the first named hydrocarbona small amount or afluorescent marker selected from the class consistingof umbelliferone and umbelliferone derivatives, extracting thehydrocarbon mixture with an aqueous alkaline solution,, and thenexamining th extract under suitable light means for detecting thefluorescence of said marker.

2. The method of identifying a normally non-gaseous hydrocarboncomprising dissolving therein a small amount of a fluorescent markerselected from the class consisting of umbelliferone and umbelliferonederivative, xtracting the A thorough rinsing with hot 1 hydrocarbon withan aqueous alkaline solution and subjecting the aqueous alkalinesolution xtract to light means capable of detecting the fluorescence ofsaid marker.

3. The method of identifying normally liquid and solid petroleumproducts comprising dissolving therein a small amount of a fluorescentmarker selected from the class consisting of an umbelliferone andumbelliferone derivatives, extracting the petroleum product with anaqueous alkaline solution, and detecting the presence of said marker bysubjecting the aqueous alkaline extract of the petroleum product tolight means capable of exhibiting the fluorescence of said marker.

4. The method described in claim 3 in which the umbelliferone derivativeis beta methyl umbelliferon.

' 5. The method described in claim 3 in which the marker isumbelliferone.

6. The method of detecting the contamination of a petroleum oil byanother petroleum oil comprising adding to the latter, prior toadmixture with the former, a small amount of a fluorescent markerselected from the class consisting of umbelliferone and umbelliferonederivatives, extracting the admixed petroleum oils. with an'aqueousalkaline solution and examining the alkaline extract under suitablelight means for detecting the fluorescence of said marker.

7. The method of detecting the contamination of crude oil by anothercrude oil comprising adding to the latter, prior to admixture with theformer, a small amount of a fluorescent marker selected from the classconsisting of umbelliferone and umbelliferone derivatives, extractingthe admixed crude oils with an aqueous alkaline solution, separating theclear alkaline aqueous solution fromthe oil and subjecting the clearalkaline aqueous solution to ultraviolet light for detecting thepresence of the fluorescent marker therein.

8. The method of identifying normally liquid and normally solidpetroleum products comprising dissolving therein a small amount of aketone solution of a fluorescent marker selected, from the classconsisting of umbelliferone and an umbelliferone derivative, extractingthe petroleum product with an aqueous alkaline solution and subjectingthe alkaline solution to a suitable li ht source adapted to exhibit thefluorescence of said marker.

9. The method described in claim 7 in which the alkaline solution is asolution of sodium

